Book summarizer

Book Summarizer Skill

Produces a single self-contained HTML file summarising every chapter of a PDF book. Target audience: complete beginners — assume zero domain knowledge.

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Step 0 — Gather user preferences (ALWAYS do this first)

Before touching the PDF, ask the user two things in a single message:

1. Where would you like the output file saved?
   Default: /mnt/user-data/outputs/book_summary.html
   (You can give a full path, or just a filename — I'll place it in the outputs folder.)

2. Are there any chapters you'd like to skip or prioritise?
   Default: process all chapters in order.

Wait for their reply. If they don't specify a path, use the default. Sanitise the path: if they give a bare filename (e.g. my_book.html), prepend /mnt/user-data/outputs/. Ensure the extension is .html.

Store the resolved path as OUTPUT_PATH — use it everywhere in Steps 3 and 6.

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Step 1 — Read the PDF

First, run a content inventory:

pdfinfo /mnt/user-data/uploads/<filename>.pdf
pdffonts /mnt/user-data/uploads/<filename>.pdf
pdftotext -f 1 -l 1 /mnt/user-data/uploads/<filename>.pdf - | head -30

Then extract all text:

pdftotext -layout /mnt/user-data/uploads/<filename>.pdf /tmp/book_text.txt

If pdffonts shows no fonts (scanned PDF), rasterize pages instead:

pdftoppm -jpeg -r 150 /mnt/user-data/uploads/<filename>.pdf /tmp/page
# then view each image for OCR-level reading

Read /tmp/book_text.txt (or rasterized pages) to understand:

• The book title, author, and domain
• The table of contents — chapter titles and page ranges
• The tone and depth of writing (beginner, intermediate, advanced)

While reading the table of contents, collect for each chapter:

• Title and page range
• Approximate page count → used to estimate reading time (assume 200 words/page, 200 wpm)
• Subjective difficulty signal: scan opening paragraphs for jargon density → assign Beginner / Intermediate / Advanced badge

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Step 2 — Analyse each chapter

For each chapter (respecting any skip/prioritise choices from Step 0):

pdftotext -f <start_page> -l <end_page> -layout /mnt/user-data/uploads/<filename>.pdf /tmp/ch_N.txt

Process each chapter through this analytical lens:

Question	Purpose
What is the chapter trying to teach?	Central thesis
What are the 3–7 most important ideas?	Key takeaways
What new words or terms does it introduce?	Glossary
What real-world thing behaves like this concept?	Analogy candidates
Why would a beginner care about this?	"Why it matters" hook
What are 3 questions to test understanding?	Review questions
Which concepts in earlier chapters does this build on?	Concept connections

For math/formula/code-heavy chapters: Do NOT reproduce the formulas or code. Instead, explain what the formula or algorithm achieves and why it matters in plain English. Focus on the intuition, not the mechanics.

Concept connection tracking: Maintain a running list of key terms introduced per chapter (e.g. {ch1: ["model", "training", "loss function"], ch2: [...], ...}). When a later chapter uses a term from an earlier one, note it — this powers the "Builds on" cross-reference links in the sidebar and chapter headers.

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Step 3 — Build the HTML output

Generate a single self-contained HTML file at OUTPUT_PATH.

The HTML must include everything inline (no external CDN dependencies) — fonts via @import from Google Fonts is acceptable.

Required structure per chapter section

Every chapter section must contain all seven of these blocks, in order:

1. Chapter header — number, title, one-sentence summary, difficulty badge, and estimated reading time (e.g. "~12 min read")
2. Key Takeaways — 3–7 bullet points, each a complete plain-English sentence
3. Core Concepts Explained — one subsection per major concept:
   • Concept name as a subheading
   • 2–4 paragraph plain-English explanation (no jargon without immediate definition)
   • A clearly labelled Real-World Analogy box for each concept
4. Why It Matters — a callout box: 2–3 sentences on practical relevance
5. Builds On — a compact row of pill-shaped links to earlier chapters whose concepts this chapter relies on (skip if chapter 1 or no dependencies)
6. Mini Glossary — key terms introduced in this chapter, defined in one sentence each, with a 📋 copy-to-clipboard button per term
7. Review Questions — exactly 3 questions a beginner should be able to answer, each in a <details> card with the answer hidden by default

Required global structure

<progress bar>          ← thin reading-progress strip at very top of viewport
<sidebar>               ← chapter list with difficulty badges + read-time; scrollspy active state
<main content area>     ← book header, then all chapter sections sequentially
<dark/light toggle>     ← top-right fixed button, persists via localStorage
<back-to-top button>    ← bottom-right fixed, appears after 300px scroll
<search bar>            ← inside sidebar header; filters chapter list by keyword live

Sidebar chapter list item structure

Each sidebar nav entry must show:

[difficulty badge]  Chapter N
                    Chapter title
                    ~N min read

Difficulty badge colours:

• Beginner → green pill (#2D7A4F bg, white text)
• Intermediate → amber pill (#B45309 bg, white text)
• Advanced → red pill (#991B1B bg, white text)

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Step 4 — HTML design spec

Read /mnt/skills/public/frontend-design/SKILL.md before writing a single line of CSS. Then apply these constraints specific to this skill:

Aesthetic direction

• Feel: Academic but warm. Like a well-designed university textbook meets a modern product documentation site. Not corporate, not hacker-dark.
• Signature element: Each "Real-World Analogy" block has a distinctive left-border colour accent and a subtle background tint — make this the most visually memorable repeated element in the document.

Colour tokens (light mode)

--bg-primary:     #FAFAF8;
--bg-secondary:   #F0EEE9;
--bg-accent:      #FFF8EE;
--text-primary:   #1A1A18;
--text-secondary: #5A584F;
--text-muted:     #8A8880;
--accent:         #C75B2A;
--accent-soft:    #E8936A;
--success:        #2D7A4F;
--warning:        #B45309;
--danger:         #991B1B;
--border:         #E0DDD6;

Dark mode (prefers-color-scheme + toggle class .dark on <html>):

--bg-primary:   #18181A;
--bg-secondary: #222226;
--bg-accent:    #2A2416;
--text-primary:   #F0EEE9;
--text-secondary: #A8A69E;
--text-muted:     #6A6860;
--accent:       #E8936A;
--accent-soft:  #C75B2A;
--success:      #4AAF76;
--warning:      #D97706;
--danger:       #EF4444;
--border:       #333330;

Typography

font-family: 'Playfair Display', Georgia, serif;   /* chapter titles */
font-family: 'Source Serif 4', Georgia, serif;     /* body text */
font-family: 'Inter', system-ui, sans-serif;       /* UI, labels, glossary */

Import from Google Fonts at the top of <style>.

Layout

• Sidebar: 260px fixed left, full viewport height, independently scrollable
• Main: margin-left: 260px, max-width 760px, auto side margins
• Mobile (< 768px): sidebar hidden behind hamburger toggle
• Chapter sections: separated by decorative large chapter number in --text-muted (opacity 0.18)

Component specs

Analogy block:

border-left: 4px solid var(--accent);
background: var(--bg-accent);
border-radius: 0 8px 8px 0;
padding: 1rem 1.25rem;
/* Label: "💡 Analogy" — Inter, 0.68rem, uppercase, letter-spacing 0.1em */

Why It Matters block:

border-left: 4px solid var(--success);
background: color-mix(in srgb, var(--success) 8%, var(--bg-primary));
border-radius: 0 8px 8px 0;
padding: 1rem 1.25rem;
/* Label: "✦ Why It Matters" */

Builds On row:

/* Horizontal flex row of pill links */
/* Each pill: bg var(--bg-secondary), border var(--border), Inter 0.75rem */
/* On hover: border-color var(--accent), color var(--accent) */
/* Label above row: "🔗 Builds On" — muted, uppercase */

Glossary:

/* Two-column grid on desktop, one column on mobile */
/* Term: Inter bold, var(--accent) */
/* Definition: Source Serif 4, var(--text-secondary) */
/* Copy button: small icon button, fades in on hover, shows "✓ Copied!" for 1.5s */

Review question cards:

/* <details> element, bg var(--bg-secondary), border var(--border), border-radius 8px */
/* Q-prefix badge in var(--accent), answer revealed on open */

Difficulty badge:

/* Inline pill: Inter 0.65rem bold, border-radius 20px, padding 0.15rem 0.5rem */
/* Colours per level: see Step 3 */

Back-to-top button:

position: fixed; bottom: 1.5rem; right: 1.5rem;
/* Hidden until scrollY > 300; fade in/out */
/* Round button, bg var(--bg-secondary), border var(--border) */

Print stylesheet

Include a @media print block that:

• Hides sidebar, progress bar, toggle, back-to-top, and search
• Sets margin-left: 0 on main, removes fixed positioning
• Forces light-mode colours regardless of .dark class
• Adds chapter URL as footer via content: attr(href) on links
• Sets page-break-before: always on each .chapter-section

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Step 5 — JavaScript requirements (all inline)

// 1. Dark/light toggle
//    localStorage('theme') → apply .dark to <html> on load
//    Toggle writes back to localStorage

// 2. Scrollspy
//    IntersectionObserver on each .chapter-section
//    Highlights matching sidebar link; rootMargin: '-20% 0px -60% 0px'

// 3. Reading progress bar
//    scroll → scrollY / (scrollHeight - innerHeight) * 100 → bar width

// 4. Sidebar mobile toggle
//    Hamburger at < 768px → toggles .sidebar-open on <body>
//    Close when nav link clicked

// 5. Sidebar search / filter
//    input event on search field → show/hide nav <li> items by matching
//    chapter title text (case-insensitive); show "No results" if all hidden

// 6. Glossary copy-to-clipboard
//    Each copy button → navigator.clipboard.writeText(term + ': ' + definition)
//    Button text changes to "✓" for 1500ms then resets

// 7. Back-to-top button
//    scroll → show/hide based on scrollY > 300
//    Click → window.scrollTo({ top: 0, behavior: 'smooth' })

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Step 6 — Quality checklist before saving

• User-specified OUTPUT_PATH is used (not hardcoded default if user gave a custom path)
• Every chapter has all 7 required blocks
• Chapter header shows difficulty badge + estimated reading time
• Builds On pills are present for chapters with concept dependencies; absent for ch1
• Sidebar search input is present and filters the chapter list
• Each glossary term has a working copy-to-clipboard button
• Back-to-top button is present and hidden initially
• Print stylesheet is included
• No unexplained jargon — every term is defined inline or in the glossary
• Analogy blocks use concrete everyday comparisons
• Math/formulas/code described in plain English only
• Dark mode colours pass WCAG AA contrast
• HTML file is fully self-contained

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Step 7 — Output

Save the file to OUTPUT_PATH, then call present_files with that path.

Tell the user:

• Book title, author, and total chapters processed
• The exact file path where the output was saved
• Any chapters skipped or that had extraction issues
• Tip: dark/light toggle top-right; sidebar search filters chapters; glossary terms are copyable; Ctrl+P / ⌘+P gives a clean print layout